Counselors working for 988, the National Suicide Prevention Lifeline, have answered more than 10 million calls, texts and chat messages in the two years since it debuted, federal officials announced this week.

The hotline was designed to simplify emergency calls and to help address the growing mental health crisis in the United States, The New York Times reports. The hotline previously used a traditional 10-digit number instead of the three-digit 988.

Of the 10 million contacts answered in the past two years, 1.7 million were texts – with 988 answering 51% more texts in the past 12 months than the year before.

A poll released this week by Ipsos and the National Alliance on Mental Illness (NAMI) found that while two-thirds of Americans have at least heard of 988, only 23% are familiar with what 988 is and the response someone would receive when reaching out for help.

“After two years of 988, millions of people have already received help for a mental health crisis or other emotional distress. As we look to year three, NAMI’s new poll shows that we’re only scratching the surface on getting the word out about this life-saving resource,” NAMI Chief Executive Officer Daniel H. Gillison, Jr. said in a news release.